High-pressure Roll Presses
These consist of a pair of rollers set 8–30 mm apart and counter-rotating with surface speed around 0.9 - 1.8 m.s−1. The bearings of the rollers are designed to deliver a pressure of 50 MPa or more. The bed of material drawn between the rollers emerges as a slab-like agglomeration of highly fractured particles. The energy efficiency of this process is comparatively high. Systems have been designed, including a de-agglomerator and separator, that will deliver material of cement fineness. However, particle size distribution is again a problem, and roll presses are now increasingly popular as a "pre-grind" process, with the cement finished in a single chamber ball mill. This gives good cement performance, and reduces energy consumption by 20-40% compared with a standard ball mill system.
Read more about this topic: Cement Mill
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